#include <cstdio>
#include <cstring>
#include <cmath>
#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

const double MAX_DISTANCE = 1.414 * 1000;

typedef struct _point
{
    double x;
    double y;
    int index;
}point;

double round( double value, int pos )
{
    double temp;
    temp = value * pow( 10, pos );
    temp = floor( temp + 0.5 );
    temp *= pow( 10, -pos );
    return temp;
}

int main()
{
    int C;
    scanf("%d", &C);
    while(C--)
    {
        int base_num;
        vector<point> bases;
        scanf("%d", &base_num);
        for(int i = 0 ; i < base_num ; i++)
        {
            point input;
            scanf("%lf %lf", &input.x, &input.y);
            input.index = i;
            bases.push_back(input);
        }
        double distances[100][100];
        for(int i = 0 ; i < base_num ; i++)
        {
            for(int j = 0 ; j < base_num ; j++)
            {   distances[i][j] = (i == j) ? 0 : sqrt(pow(abs(bases[j].x - bases[i].x), 2) + pow(abs(bases[j].y - bases[i].y), 2)); }
        }
        // Prim
        vector<double> my_tree;
        bool * is_checked = new bool[base_num];
        memset(is_checked, false, base_num);
        is_checked[0] = true;
        int current;
        bool OK = false;
        for(int i = 0 ; i < base_num - 1 ; i++)
        {   
            double shortest = MAX_DISTANCE;
            for(int j = 0 ; j < base_num ; j++)
            {   
                if(is_checked[j] == true)
                {
                    for(int k = 0 ; k < base_num ; k++)
                    {
                        if(j != k && is_checked[k] == false)
                        {   
                            if((distances[j][k] < shortest))
                            {
                                shortest = distances[j][k]; 
                                current = k;    
                            }
                        }
                    }
                }
            }
            is_checked[current] = true;
            my_tree.push_back(shortest);
        }
        printf("%4.2lf\n", round(*max_element(my_tree.begin(), my_tree.end()), 3));
    }
    return 0;
}